The First Silver-Catalyzed Three-Component Coupling of Aldehyde, Alkyne, and Amine
Chunmei Wei, Zigang Li and Chao-Jun Li*
*Department of Chemistry, McGill University, 801 Sherbrooke St. West, Quebec
H3A 2K6 Canada, Email: cj.limcgill.ca
C. Wei, Z. Li, C.-J. Li, Org. Lett., 2003, 5, 4473-4475.
DOI: 10.1021/ol035781y
Abstract
A three-component coupling between an aldehyde, alkyne and amine is catalyzed by silver iodide to generate propargylic amines in high yields in water without cocatalyst or activator. This method is especially effective for reactions involving aliphatic aldehydes.
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The document reports the first silver-catalyzed three-component coupling of aldehyde, alkyne, and amine to produce propargylic amines efficiently in water. The reaction, catalyzed by silver iodide (AgI), is particularly effective for aliphatic aldehydes, yielding high conversions and minimal by-products without the need for additional cocatalysts or activators. This method contrasts with previous systems where aromatic aldehydes were more reactive. Various silver salts were tested, with AgI proving the most effective, achieving a 75% conversion rate. The reaction works well in both water and organic solvents like toluene and DMF, with high yields even at low catalyst concentrations. The proposed mechanism involves the formation of a silver acetylide intermediate, which reacts with an iminium ion generated in situ. This environmentally friendly method offers a greener alternative to traditional Barbier-Grignard-type reactions, aligning with the principles of green chemistry. The study highlights the potential of silver as a catalyst in organic synthesis, challenging the notion of its low efficiency compared to other transition metals. Further investigations into the scope, mechanism, and applications of silver-catalyzed couplings are ongoing. The research was supported by NSF and the NSF-EPA joint program for a sustainable environment.
C. Wei, C.-J. Li, J. Am. Chem. Soc., 2003, 125, 9584-9585.
Key Words
alkynes, multicomponent reactions, propargylamines, green chemistry
ID: J54-Y2003-1130